Hub vs switches

[forum_84]

hi,
If the switch is of 100Mbps, and has 5 workstations connected to it output link, it is said that all 5 worstations receive 100Mbps. Assume all worstations are using heavy traffic with almost equal to 100Mbps, how is this poossible with the input of 100mbps and output is 5x100Mbps??

 

[tigsounds]

From the switch WAN port, 100Mbps total data flow can occur. From one port to another, 100Mbps can occur simultaneously as long as one of those ports is not involved with the WAN port.

For a hub, all ports get 100Mbps from the WAN port, but all ports receive identical data and it is the individual computers job to sort out if a particular packet is for it, or reject it because it belongs to a different machine. Machine to machine transfers must wait their turn to get data moved across a hub if the WAN port is busy. This makes the switch a smart device and a hub a dumb one.

 

[reitzell]

Two different things- data rate and link speed to the switch. Each port does have 100 Mbits/sec connection to the switch. There is the link speed to the switch that is 100Mbits/sec but the computers can not communicate at that "data rate" due to the congestion. Just because you connect to a switch at 100Mbits/sec doesn't mean you are going to transfer data at that rate.

Good luck,

 

[sk1939]

hi,
If the switch is of 100Mbps, and has 5 workstations connected to it output link, it is said that all 5 worstations receive 100Mbps. Assume all worstations are using heavy traffic with almost equal to 100Mbps, how is this poossible with the input of 100mbps and output is 5x100Mbps??

It isn't possible, Windows reports the link speed, not the actual bandwidth usage. For actual bandwidth usage, go into Performance Monitor, or look at the percent of traffic under Task Manager. As far as the heavy traffic goes, the output/uplink is 100/5, which means that each PC gets 20mbps of bandwidth a piece. Unless you are using heavy I/O (which means you really should upgrade to Gigabit) this is almost never a problem for most users.